Fine Particle pH and Sensitivity to NH3 and HNO3 over South Korea During KORUS-AQ

Authors

  • Ifayoyinsola Ibikunle School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
  • Andreas Beyersdorf NASA Langley Research Center, Hampton, VA 23681, USA
  • Pedro Campuzano-Jost Department of Chemistry, University of Colorado, Boulder, CO 80309, USA; Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA
  • Chelsea Corr NASA Langley Research Center, Hampton, VA 23681, USA; Currently at Colorado State University
  • John D. Crounse California Institute of Technology, Pasadena, CA 91125
  • Jack Dibb Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA
  • Glenn Diskin NASA Ames Research Center, Moffett Field, CA 94035, USA
  • Greg Huey School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
  • Jose-Luis Jimenez Department of Chemistry, University of Colorado, Boulder, CO 80309, USA; Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA
  • Michelle J. Kim California Institute of Technology, Pasadena, CA 91125
  • Benjamin A. Nault Department of Chemistry, University of Colorado, Boulder, CO 80309, USA; Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA; Currently at Center for Aerosol and Cloud Chemistry, Aerodyne Research Inc., Billerica, MA, USA
  • Eric Scheuer Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA
  • Alex Teng California Institute of Technology, Pasadena, CA 91125
  • Paul O. Wennberg California Institute of Technology, Pasadena, CA 91125
  • Bruce Anderson NASA Langley Research Center, Hampton, VA 23681, USA
  • James Crawford NASA Langley Research Center, Hampton, VA 23681, USA
  • Rodney Weber School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
  • Athanasios Nenes School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA; School of Architecture, Civil & Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland; Center for the Study of Air Quality and Climate Change, Institute for Chemical Engineering Sciences, Foundation for Research and Technology Hellas, Patras, GR-26504, Greece https://orcid.org/0000-0003-3873-9970

DOI:

https://doi.org/10.2533/chimia.2024.762

Keywords:

Aerosol acidity, Ambient measurements, Nitrate, Thermodynamics

Abstract

Using a new approach that constrains thermodynamic modeling of aerosol composition with measured gas-to-particle partitioning of inorganic nitrate, we estimate the acidity levels for aerosol sampled in the South Korean planetary boundary layer during the NASA/NIER KORUS-AQ field campaign. The pH (mean ± 1σ = 2.43±0.68) and aerosol liquid water content determined were then used to determine the ‘chemical regime’ of the inorganic fraction of particulate matter (PM) sensitivity to ammonia and nitrate availability. We found that the aerosol formation is always sensitive to HNO3 levels, especially in highly polluted regions, while it is only exclusively sensitive to NH3 in some rural/remote regions. Nitrate levels are further promoted because dry deposition velocity is low and allows its accumulation in the boundary layer. Because of this, HNO3 reductions achieved by NOX controls prove to be the most effective approach for all conditions examined, and that NH3 emissions can only partially affect PM reduction for the specific season and region. Despite the benefits of controlling PM formation to reduce ammonium-nitrate aerosol and PM mass, changes in the acidity domain can significantly affect other processes and sources of aerosol toxicity (e.g. solubilization of Fe, Cu and other metals) as well as the deposition patterns of these trace species and reactive nitrogen.

Funding data

Downloads

Published

2024-11-27